A seat position sensor as a position detecting sensor has been disclosed in a U.S. Patent published as U.S. Pat. No. 6,053,529. The seat position sensor includes a sensor flange mounted on a flange side of a moveable rail attached to an automotive seat, and a magnetic sensor being of U-shaped cross-section with two legs extending in an upward direction. The magnetic sensor is structurally connected to a stationary rail attached to a floor section. According to the above-described structure, the magnetic sensor can sense the sensor flange passing between the two legs of the magnetic sensor in accordance with seat movement. The sensor flange includes a first flange portion, which passes between the two legs of the magnetic sensor and interrupts magnetic polarity of the magnetic sensor, and a second flange portion, which does not pass therebetween and does not interrupt the magnetic polarity thereof. The magnetic property of the magnetic sensor varies in accordance with position of the sensor flange relative to the magnetic sensor. More particularly, the magnetic sensor outputs on or off signal in accordance with position of the sensor flange relative to the magnetic sensor, thereby enabling to detect the seat position.
However, according to the seat position sensor with the above-described structure, the sensor flange is positioned in the magnetic sensor with the U-shaped structure. In this case, space for mounting the magnetic sensor in the aforementioned manner is required, thereby deteriorating mounting performance.
In order to solve the above-described problem, according to a Japanese Patent Laid-Open Publication published as No. 2000-310646, disclosed is a rotation sensor employing a Hall IC for detecting a position of a detected member relative to the rotation sensor. More particularly, the rotation sensor employs a Hall IC—magnet pair and can be arranged at one side of the detected member, wherein the rotation sensor can be effectively downsized.
However, when an individual fluctuation occurs between the sensor and the detected member, an output from the sensor may not be able to be sufficiently obtained. Therefore, recent demands have lead to improvement of mounting precision.
The present invention therefore seeks to provide a position-detecting sensor capable of detecting a position of a detected member in a general assembling fashion even when a position of the sensor relative to the detected member widely fluctuates.